The long term goal of the PI's research is to miniaturize high-throughput screening (HTS) of lipophilic drug candidates in order to make HTS technology widely accessible. There is a well-established need to miniaturize HTS in order to reduce the cost, time, and accessibility of this process. Small molecule microarrays are a promising solution to this problem, yet are currently limited in their ability to deliver sufficien dosages to cells cultured on them in a high-throughput format without cross-contamination. The idea behind this project is to encapsulate lipophilic drug candidates within surface-supported lipid multilayer arrays, culture cells over this array, and screen for drug efficacy in a microarra format. Because lipophilic drug candidates are used, cross contamination due to leakage and diffusion of the drug candidates through the aqueous solution will be minimal. Cationic lipids developed for liposomal formulations will be used to promote cellular uptake from the surface. The suitability of lipid multilayer microarrays for HTS applications will be demonstrated by scale up of the fabrication process, determination of the stability of the arrays, and quantification of cellular uptake from the arrays. Aim 1 is to scale up the fabrication process used to produce lipid multilayer microarrays by combining established microarray technology with the novel method of lipid multilayer stamping to produce arrays with at least 1000 spots per cm2, which is >100 times the density of a standard 1536 well plate. The quality of the arrays will be determined by fluorescence microscopy and atomic force microscopy. Aim 2 is to determine the stability of the lipid multilayer microarrays after long-term storage and use in cell culture, to ensure insignificat cross-contamination between spots and accessibility of the technology to other scientists. Stability of the arrays will be assayed in storage and under cell culture conditions by fluorescence microscopy and any leakage of encapsulated compounds will be quantified by HPLC. Aim 3 is to obtain quantitative dose- response curves from an individual surface by fabricating spots of different multilayer thickness and testing, by means of toxicity assays and live-cell imaging of fluorophores delivered to the cells, of the hypothesis that multilayer thicknes determines the dosage received by the cells. The contribution of the proposed research will enable delivery of lipophilic drugs to cells in a microarray format with up to 200,000 tests on a single titer plate, making HTS widely accessible. The novel aspect of this proposal is to encapsulate lipophilic drug candidates into within lipid multilayer microarrays to allow testing of high dosages without cross-contamination.